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From:   Pavel Begunkov <asml.silence@gmail.com>
To:     Jens Axboe <axboe@kernel.dk>, io-uring@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 1/3] io-wq: don't reshed if there is no work
Date:   Sat, 14 Mar 2020 00:31:03 +0300
Message-Id: <96c4e978564b3bf3674e2dbecb60b012c8e79f81.1584130466.git.asml.silence@gmail.com>
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This little tweak restores the behaviour that was before the recent
io_worker_handle_work() optimisation patches. It makes the function do
cond_resched() and flush_signals() only if there is an actual work to
execute.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io-wq.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 0e7c6277afcb..8afe5565f57a 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -458,10 +458,12 @@ static void io_impersonate_work(struct io_worker *worker,
 static void io_assign_current_work(struct io_worker *worker,
 				   struct io_wq_work *work)
 {
-	/* flush pending signals before assigning new work */
-	if (signal_pending(current))
-		flush_signals(current);
-	cond_resched();
+	if (work) {
+		/* flush pending signals before assigning new work */
+		if (signal_pending(current))
+			flush_signals(current);
+		cond_resched();
+	}
 
 	spin_lock_irq(&worker->lock);
 	worker->cur_work = work;
-- 
2.24.0